Old transfo from Burroughs computer of the 70's

[alpibucky]

Hello,

I have an old transformator from a Burroughs Corp (Holliwood) computer.
1431-4173 appears as number on it. It is mounted on a plate. Schematics
of the power supply is 1431-4160, 4163, 4165 or 1430-4168. Assy Nr
unknow. Manufactured in 1973
There are 4 symetric outputs : 2 yellow ones with common green, 2 blue
ones with common brown. 2 orange ones with common green. 2 red ones
with common green. There is also a condensator 15F603 (2 uF, 60 Hz, 660
V AC) connected with two extra white wires. There is also a
yellow/green wire connected to the earth of the assembly.
There are 6 inputs as main with a bridge between the 3th and the 4th
wires (maybe for 220 V operation).
Does anyone have de characteristics of this transformator ?

With kinds regards

Alpibucky

 

[Cydrome Leader]

alpibucky <alpibucky@mail.be> wrote:

Hello,

I have an old transformator from a Burroughs Corp (Holliwood) computer.
1431-4173 appears as number on it. It is mounted on a plate. Schematics
of the power supply is 1431-4160, 4163, 4165 or 1430-4168. Assy Nr
unknow. Manufactured in 1973
There are 4 symetric outputs : 2 yellow ones with common green, 2 blue
ones with common brown. 2 orange ones with common green. 2 red ones
with common green. There is also a condensator 15F603 (2 uF, 60 Hz, 660
V AC) connected with two extra white wires. There is also a
yellow/green wire connected to the earth of the assembly.
There are 6 inputs as main with a bridge between the 3th and the 4th
wires (maybe for 220 V operation).
Does anyone have de characteristics of this transformator ?

The HV capacitor makes it sound like ferrorresonant power supply.

I can't explain exactly how they work, but they output a magnetically
regulated output voltage. Line input variations will not affect the
output. In fact on some of these you can input square waves and the output
remains a nice sine wave.

Their efficiency is poor, but they are simple and extremely reliable.

 

[Reinhard Zwirner]

alpibucky schrieb:

Hello,

I have an old transformator from a Burroughs Corp (Holliwood) computer.
1431-4173 appears as number on it. It is mounted on a plate.
Schematics of the power supply is 1431-4160, 4163, 4165 or 1430-4168.
Assy Nr unknow. Manufactured in 1973
There are 4 symetric outputs : 2 yellow ones with common green, 2
blue ones with common brown. 2 orange ones with common green. 2 red
ones with common green. There is also a condensator 15F603 (2 uF, 60
Hz, 660 V AC) connected with two extra white wires. There is also a
yellow/green wire connected to the earth of the assembly.
There are 6 inputs as main with a bridge between the 3th and the 4th
wires (maybe for 220 V operation).
Does anyone have de characteristics of this transformator ?

Hi,

This could be a

<Quote>
Constant voltage transformer

By arranging particular magnetic properties of a transformer core,
and installing a ferro-resonant tank circuit (a capacitor and an
additional winding), a transformer can be arranged to automatically
keep the secondary winding voltage relatively constant for varying
primary supply without additional circuitry or manual adjustment.
Ferro-resonant transformers run hotter than standard power
transformers, because regulating action depends on core saturation,
which reduces efficiency. The output waveform is heavily distorted
unless careful measures are taken to prevent this. Saturating
transformers provide a simple rugged method to stabilize an AC power
supply.
</Quote>

<http://en.wikipedia.org/wiki/Transformer_types#Constant_voltage_transformer>

You'll find additional information here (chapter 4.9, picture 4.6.1,
p. T32):

<http://www.ismet.de/sites/default/files/Technik%20Kapitel%204.pdf>

HTH

Reinhard

 

alpibucky <alpibucky@mail.be> wrote:

I have an old transformator from a Burroughs Corp (Holliwood)
computer. [...] There are 6 inputs as main with a bridge between the
3th and the 4th wires (maybe for 220 V operation).

That might be true. You might have something like this (view in a fixed
width font):

6 ----)
)
5 ----)
)
4 ----)

3 ----)
)
2 ----)
)
1 ----)

1-2 and 4-5 are probably designed for 100 V or 105 V, and 1-3 and 4-6
are probably designed for 115 V or 120 V. If you link 3 and 4, then you
can apply 230 V or 240 V mains power to 1 and 6. (With no link on 3 and
4, supplying mains to 1 and 2, and to 4 and 5, makes it work in a 100 V
mains country like Japan. With no link on 3 and 4, supplying mains to
1 and 3, and to 4 and 6, makes it work in a 120 V mains country like the
United States.)

> Does anyone have de characteristics of this transformator ?

Get another power transformer of known characteristics, like 230 V : 6 V
or 230 V : 12 V. Output of 1 or 2 A is probably more than enough.
Connect the 230 V side of this transformer (carefully) to mains power,
and then connect the 6 V or 12 V output of this transformer to the main
input of your Burroughs transformer. Measure the 6 V or 12 V output of
your known transformer, and then (carefully) measure the other outputs
of the Burroughs transformer. From that, you can determine the voltage
ratios of all the windings of the Burroughs transformer. Leave the
capacitor connected to the Burroughs transformer for this.

To figure out the power (W) ratings of each output, you can measure the
voltage with no load, then load down each output with something
(resistors, incandescent lamps) until the voltage drops 10%. The
current (A) at that point is probably pretty close to the current rating
of that output.

Read all of the following
http://www.repairfaq.org/REPAIR/F_audiofaq8.html#AUDIOFAQ_005
http://www.repairfaq.org/REPAIR/F_audiofaq8.html#AUDIOFAQ_006
http://www.repairfaq.org/REPAIR/F_audiofaq8.html#AUDIOFAQ_008
for more details.

I hope this helps!

Matt Roberds